Have you ever wondered why the Oriental Soroban abacus has 4 separate beads? It is in base 10, not 4 or 5, so why organize it that way? In response to yesterday’s post Hand tricks! Alexander Bogomolny linked his…

Posted in Make

Using one’s hands is practically intuitive in the math world. Counting on one’s fingers is the most basic mathematical practice one could think of. But there is other more complex math you and your kid can do with your hands!…

Posted in Make

Click numbers on the left and on the right to set up an example: This Flash applet teaches you how to compute times tables from 6 to 10, on your fingers. The trick was first recorded around 15th century, when…

Posted in Grow

Want to participate in citizen science, collecting data of children’s math art? Happy to display your child’s creations beyond your the fridge? Then send us grid drawings! Thank you, Alexia Idoura, Maria Genkin, and Dan White for sharing your children’s…

Posted in Make